1 files changed, 90 insertions, 0 deletions
diff --git a/src/core/NEON/kernels/convolution/common/qasymm8.cpp b/src/core/NEON/kernels/convolution/common/qasymm8.cpp
new file mode 100644
index 0000000000..1de9ebf28a
--- /dev/null
+++ b/src/core/NEON/kernels/convolution/common/qasymm8.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2019 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cmath>
+#include <limits>
+
+#include "arm_compute/core/NEON/kernels/convolution/common/qasymm8.hpp"
+
+namespace qasymm8
+{
+#if(__ANDROID__ || BARE_METAL)
+template <typename T> T round(T val) {  return ::round(val); }
+template <typename T> T exp2(T val) { return ::exp2(val); }
+template <typename T> T log2(T val) { return ::log2(val); }
+#else  /* (__ANDROID__ || BARE_METAL) */
+template <typename T> T round(T val) { return std::round(val); }
+template <typename T> T exp2(T val) { return std::exp2(val); }
+template <typename T> T log2(T val) { return std::log2(val); }
+#endif  /* (__ANDROID__ || BARE_METAL) */
+
+uint8_t QAsymm8Params::quantize(const float value) const
+{
+  const float transformed = value / scale + offset;
+  return static_cast<uint8_t>(round(std::max(0.0f, std::min(255.0f, transformed))));
+}
+
+float QAsymm8Params::dequantize(const uint8_t value) const
+{
+  return scale * (static_cast<float>(value) - offset);
+}
+
+QAsymm8RescaleParams QAsymm8RescaleParams::make_rescale_params(
+  const QAsymm8Params& weight_quant,
+  const QAsymm8Params& input_quant,
+  const QAsymm8Params& output_quant
+)
+{
+  // Based on the gemmlowp approach: https://github.com/google/gemmlowp/blob/master/doc/quantization_example.cc
+  const float rescale = weight_quant.scale * input_quant.scale / output_quant.scale;
+  const float shiftf = round(log2(0.5f / rescale));
+  const float multf = exp2(31.0f + shiftf)*rescale;
+
+  int64_t shift = static_cast<int64_t>(shiftf);
+  int64_t mult = static_cast<int64_t>(multf);
+
+  if (mult == (1ll << 31))
+  {
+    mult /= 2;
+    shift--;
+  }
+
+  assert(shift >= 0);
+  assert(mult <= std::numeric_limits<int32_t>::max());
+
+  return QAsymm8RescaleParams(
+    static_cast<int32_t>(shift),
+    static_cast<int32_t>(mult),
+    rescale
+  );
+}
+
+QAsymm8RescaleParams::QAsymm8RescaleParams(int32_t shift, int32_t multi, float rescale)
+  : shift(shift), multiplier(multi), rescale(rescale)
+{
+}
+}